Fusible link.



No. 725,495. PATENTED APR. 14, 190.3.

0. B. SHAW &'W.`B. KNIGHT.

FUSIBLE LINK. APrLIoATIoN FILED APB. im. 1902.

B0 MODEL.

NITED 'STATES PATENT OFFICE.

CAMPBELL B. SHAW, OF KIRKWOOD, AND WILLIAM B. KNIGHT, OF ST. LOUIS, MISSOURI; SAID KNIGHT ASSIGNOR TO HARRY SCULLIN, OF

ST. LOUIS, MISSOURI.

FUSIBLE LINK.

SPECIFICATION forming part of Letters raam-Na 725,495, atea April-14, 1903.

Application ned April 2:51902.

Our invention relates to a fusible link for.

use in connection with automaticsprinklers of fire-extinguishing apparatus or other mechanical devices the parts of which it is desired to hold in assembled condition pending the presence of sufficient heat to melt an easily fusible connection by which the mem` l to theincline 5, so as to provide a pocket at bers of the link are united.

Our invention consists in features of novelty hereinafter fully described, and pointedv Y of eachlink-plate has a fiat surface 8, that out in the claims.

Figure I is a perspective view showing the inside face of one of the pair of mating linkplates of our link. Fig. II is a perspective"4 view showing the outside face of the secondi Fig. III is a perspective view of' link-plate. the fulcrum member used .between the linkplates shown in Figs. I and II. Fig. IV is a perspective view of our link in assembled condition ready for-use. Fig. V is a longitudinal section taken through the link in its dismembered condition, illustrating the manner in which the parts move when pulled apart. Fig. VI is a longitudinal section taken through a link in assembled condition and illustrating a construction wherein the links are separated by a longitudinal thrust in'- stead of a pulling action.' Fig. VII is a perspectiveview illustrating a link constructed in accordance with our invention and having Hat edges with a sealing-gasket located between them for the purpose of preventing the formation of a corrosive connection between the link-plates. Fig. VIIIis a cross-section taken on line VIIIVIII, Fig. VII.v

1 l designates the two plates that `are designed to be assembled toconstitute our link. These plates are'adapted to be placed together, with their outer ends disposed in opposite diseriai no. 104,918. (No man.)

motions; but they are counterparts,and therefore similar reference characters will be applied to Yeach in describing theirconstruction.

Each plate l is provided at itsk outer end with an aperture 2, adapted topreceive parts to be connected by the link when assembled. At theinside face of each plate is a flat surface 3, that preferably extends inwardly from the outer end of the plate to a point approximately central of the length of the plate. At the inner terminus of the flat surface 3y of each plate is a bead or projecting portion 4, that extends from the inner face of the plate. Beginning at the bead 4, each plate is inclined rearwardly, as shown at 5, the incline extending to a point 6. (See-Figs. I and II.) From the point` 6 each plate ex` tendsforwardly at an angle, as shown at 7,

the junction of the inclined portion and the forward angle portion at 7. The inner end extends from the angle portion 7 to the inner terminus of the plate.

9 istJ fulcrum-block that is adapted to be positioned between the two meeting andoppsinglink-plates 1 when the plates are placed together in opposite directions, so that one edge .ofthe fulcrum-blockwill occupy theV4 pocket provided by the inclined portion 5 and angle portion 7 of one plate and be held therein by the bead or projection 4 of the other plate, as seen in Fig. IV, while the other edge ofthe fulcrum-block occupies the pocket of the other plate in like manner and is held therein by the bead or projection of the rstnamed plate. The link-plates are united by solder fusible at alow temperature, as shown .at A,which is applied to the'at opposing faces IIIand VIII of the plates, as seen in Fig. IV. In the practical use of our link it is applied to the article in connection with which it is to be used after the parts have been assembled, as described and as shown inFig. i

IV.v When sufficient heat occurs inthevicinity of the link to fuse the solder A","itbecomes fused, and the strainl upon the linkplates normally present inthe article to which the link is applied creates a pull upon the plates that tends to draw them apart. When Ico this occurs, the fulcrum-block 9, located in the pockets of the two plates, is carried by such plates in a rocking manner and fulcruming between them rocks them asunder, as seen in Fig. V, thereby immediately breaking the connection attained by the solder body, quickly and efficiently freeing the links from each other, so as to permit the movement of the parts previously united by the link.

In Fig. VI We have shown a construction wherein the link-plates are adapted to receive an end thrust instead of a pull for the purpose of thrusting them inwardly, and thereby causing the fulcruming of the fulcrum-block between them by such thrust instead of a pull. To obtain this result, it is only necessary to have the outer ends of the links extend from the angle portion 7 of the linkplates instead of from the beads or projections 1.

Itis a well-kuown fact that in the sprinklerheads of all fire-extinguishing apparatus the greatest dificulty to be contended with is that of corrosion, which occurs on the parts of the apparatus which are connected by fusible solder. This corrosion forms a coating that connects the lnembers united by solder and holds them from separation when the solder is softened by the action of heat thereupon.

In Figs. VII and VIII we have shown a construction whereby the formation of corrosion from one link-plate to the other may be obviated. In this construction the plates are widened beyond the portions at, 5, 6, and 7, so as to provide dat extensions l0, that meet the lat ends of the link-plates. Between the plates we place a gasket 1l, that preferably extends beyond the edges of the plates and may be of any desirable material, but is preferably of tin. By the introduction of the gasket l1, which is of a material not readily attacked by corrosion, such as tin, any corrosive coating that results on the link-plates is kept separated from uniting across the space between the plates in which the fusible solder is contained, to thereby form a bond connecting the plates. By extendingthis gasket l1, as illustrated in Figs. VII and VIII, it will be seen that their utility is materially enhanced, inasmuch as the projecting edge of the gasket constitutes a widened border around which there is no liability of the corrosive coating on thelink-plates extending to form a bond between them.

-We claim as our inventionl. A fusible link comprising a pairofplates provided with pockets, a fulcrum-block 1ocated between said plates in said pockets, and projections carried by said plates at ends of said pockets and arranged to bear against the sides of said fulcrum-block to hold the block seated in said pockets, subst-an tially as described.

2. A fusible link comprising a pair of plates provided with pockets, a fulcrum-hlock located between said plates and seated in said pockets, and beads carried by said plates at ends of said pockets and arranged to bear against the sides of said fulcrum-block to hold the block seated in said pockets, substantially as described.

3. In a fusible link, the combination of a pair of plates each having attened portions at their ends, inclined portions and meeting angle portions intermediate of their ends, beads at one termination of each of said inclined portions, and a fulcrum-block located between said plates and seated in the pockets provided by said inclined and angle portions, substantially as described.

4. In a fusible link, the combination with a pair of plates adapted to be connected by solder, of a gasketlocated between said plates at their edges, substantially as described.

5. In a fusible link, the combination with a pair of plates adapted to be connected by solder, of a gasket located between said plates and extending beyond the edges of said plates, substantially as described.

CAMPBELL B. SI'IAVV. VILLIAM B. KNIGHT. In presence of- E. S. KNIGHT, M. P. SMITH. 

